1. Field of the Invention
The present invention relates to an apparatus and method for performing image processing on a three-dimensional medical image representing a subject's internal structure having a branch structure and a surrounding structure, such as a lung. The invention also relates to a computer readable recording medium on which is recorded a program for the same.
2. Description of the Related Art
An image processing method for diagnosing embolization of a pulmonary blood vessel based on a three-dimensional medical image representing a chest region is known.
For example, U.S. Pat. No. 7,583,829 proposes a method in which a pulmonary blood vessel system is divided into segments, then an embolization area in the pulmonary blood vessel system after the segmentation is identified manually or automatically, a blood vessel sub-tree affected by the identified embolization is analyzed to identify a lung area affected by the embolization, and the lung area is visually displayed.
Further, U.S. Pat. No. 7,715,608 proposes a method in which segmentation of pulmonary parechymal tissue is performed on a CT image representing both lungs, then a perfusion map of the segmented image is generated, and an abnormally underperfused area is rendered and displayed comparatively opaque.
The method described in U.S. Pat. No. 7,583,829, however, only visualizes a lung area affected by embolization of a pulmonary blood vessel and does not indicate how the pulmonary function has been changed in the area.
In the mean time, it is difficult to locally evaluate pulmonary function, like a lung area affected by the embolization of a pulmonary blood vessel, by the method described in U.S. Pat. No. 7,715,608 since the method visualizes a perfusion map of the entire lungs.
The present invention has been developed in view of the circumstances described above and it is an object of the present invention to provide a medical image processing apparatus and method that allows, based on a three-dimensional medical image representing a subject's internal structure having a branch structure and a surround structure, easy observation or evaluation for functional and/or morphological characteristics of an area of the surrounding structure functionally associated with an attention portion of the branch structure. It is a further object of the present invention to provide a computer readable recording medium on which is recorded a medical image processing program of the present invention.